1. Field of the Invention
This invention relates to an electrosurgical apparatus and method and more particularly relates to signal generation suitable for use in producing electrosurgical coagulation currents.
2. Description of the Prior Art
Heretofore, varying types of electrosurgical generators have been proposed and/or utilized that have been capable of generating cutting and/or coagulation currents. As is well known, such an electrosurgical generator supplies electrical power to be used for localize heating of tissues in surgical cutting and surgical coagulating. Such a generator is shown, for example, in U.S. Pat. No. 3,699,967, issued Oct. 24, 1972. In order to prevent nerve stimulation, the power supply to the tissues must be supplied at radio frequencies, and for surgical coagulation, electrical current passes from an electrode to the body tissue in the form of an arc. In order to generate such an arc, the electrosurgical generator must have a high voltage capability both to start and sustain such an arc. While electrosurgical generators suitable for producing surgical coagulation currents have been proposed and used heretofore, none of these electrosurgical generators have been found to be completely successful for at least some purposes, and it has been found that at least some such generators have requied expensive and complicated circuitry, have been limited in performance capabilities, and/or have not been as efficient in operation as thought desirable.